Su­per­sonic Speed De­stroys Body

The V-2 rocket is the first to travel faster than the speed of sound, but at such a ve­loc­ity, even the slight­est in­sta­bil­ity could be dis­as­trous.

Be­fore the V-2, no air­craft had ever trav­elled faster than the speed of sound (about 1,200 km/h). The Ger­man rocket trav­els 4.5 times this speed, putting heavy de­mands on its aero­dy­namic sta­bil­ity.

One par­tic­u­lar prob­lem is its de­scent to­wards the tar­get. When the V-2 rocket trav­els through the lower layer of the at­mos­phere at a speed of about 5,700 km/h, the air builds up in a bow wave, in­creases drag, and can even cause the V-2 to ex­plode.

The Ger­mans do any­thing in their power to de­velop a stream­lined and sturdy de­sign. Four fins are curved into a new, "brushed back" shape – like the tail feather of an ar­row – as ex­per­i­ments in some of the world’s largest wind tun­nels show that this will re­duce tur­bu­lence and pres­sure at su­per­sonic speeds. The rocket’s skin is also strength­ened. Wind tun­nel ex­per­i­ments with heat sen­sors show that the rocket’s sur­face is heated to 805°C at su­per­sonic speeds, as fric­tion in­creases. Aero­dy­nam­ics ex­perts use the knowl­edge to built the V-2 with the ideal type of steel to coun­ter­act break-ups.

Vanes force the rocket's cen­tre of pres­sure back to the rear end, pre­vent­ing it from "fall­ing over" at high speeds. ROCKET FINS COUN­TER­ACT SOMERSAULTS